scholarly journals Antimicrobial Resistance of Streptococci Isolated from Mastitic Bovine Milk Samples in Korea

2009 ◽  
Vol 21 (5) ◽  
pp. 698-701 ◽  
Author(s):  
Hyang-Mi Nam ◽  
Suk-Kyung Lim ◽  
Hyun-Mi Kang ◽  
Jae-Myoung Kim ◽  
Jin-San Moon ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agent ◽  
High Resistance ◽  
Antimicrobial Agents ◽  
Bovine Milk ◽  
Individual Species ◽  
Streptococcus Salivarius ◽  
Milk Samples ◽  
Streptococcus Species ◽  
The Individual

The aim of the current study was to determine the antimicrobial resistance of streptococci isolated from mastitic bovine milk samples. A total of 178 isolates belonging to 6 different Streptococcus species were examined: S. uberis (n = 99), S. bovis ( n = 30), S. oralis ( n = 24), S. salivarius ( n = 13), S. intermedius ( n = 7), and S. agalactiae ( n = 5). Only 8.9% (16/178) of the isolates were susceptible to all antimicrobial agents tested in this study, and S. agalactiae and S. intermedius isolates were all resistant to at least 1 antimicrobial agent tested. Overall, the most frequently observed resistance was to tetracycline (61.2%), followed by lincomycin (43.2%), gentamycin (35.3%), oxacillin (34.3%), and erythromycin (28.6%). Cephalothin and penicillin were the only antimicrobial agents to which most of the streptococci (92%) were susceptible. Wide differences in the prevalence of resistance are apparent among the individual species: S. salivarius displayed exceptionally high resistance to cephalothin (23.0%) and oxacillin (76.9%) and S. agalactiae (20%) and S. intermedius (14.2%) to penicillin. Streptococcus salivarius and S. agalactiae were all susceptible to erythromycin, but others showed various rates of resistance ranging from 12.5% to 42.8%. Resistance to 3 or more of 7 antimicrobial agents was observed in all species (37.6%, 67/178).

scholarly journals Antimicrobial resistance and virulence characteristics in 3 collections of staphylococci from bovine milk samples

2021 ◽  
Author(s):  
M.E. Fergestad ◽  
A. De Visscher ◽  
T. L'Abee-Lund ◽  
C. Ngassam Tchamba ◽  
J.G. Mainil ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bovine Milk ◽  
Milk Samples

Biofilm Susceptibility to Antimicrobials

1997 ◽  
Vol 11 (1) ◽  
pp. 160-167 ◽  
Author(s):  
P. Gilbert ◽  
J. Das ◽  
I. Foley
Keyword(s):  
Antimicrobial Agents ◽  
Soft Tissues ◽  
Individual Species ◽  
Biofilm Growth ◽  
Chemical Gradients ◽  
Microbial Biofilms ◽  
Physico Chemical ◽  
Solid Substratum ◽  
The Individual ◽  
Micro Organisms

Microbial biofilms, where organisms are intimately associated with each other and a solid substratum through binding and inclusion within an exopolymer matrix, are widely distributed in nature and disease. In the mouth, multispecies biofilms are associated not only with dental plaque and tooth decay but also with soft tissues of the buccal cavity and with most forms of periodontal disease. Organization of micro-organisms within biofilms confers, on the component species, properties which are not evident with the individual species grown independently or as planktonic populations in liquid media. While many of these properties relate to the establishment of functional, mixed-species consortia within the exopolymeric matrices, others relate to the establishment of physico-chemical gradients, within the biofilm, that modify the metabolism of the component cells. A consequence of biofilm growth that has profound implications for their control in the environment and in medicine is a markedly enhanced resistance to chemical antimicrobial agents and antibiotics. Mechanisms associated with such resistance in biofilms will form the substance of the present review. While some aspects of biofilm resistance are yet only poorly understood, the dominant mechanisms are thought to be related to: (i) modified nutrient environments and suppression of growth rate within the biofilm; (ii) direct interactions between the exopolymer matrices, and their constituents, and antimicrobials, affecting diffusion and availability; and (iii) the development of biofilm/attachmentspecific phenotypes.

scholarly journals Μελέτη της επίδρασης συσκευασίας και φυσικών αντιμικροβιακών παραγόντων στην ποιότητα και υγιεινή παραδοσιακών ελληνικών προϊόντων - τροφίμων

2012 ◽  
Author(s):  
Μαρία Τσιράκη
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agent ◽  
Bacillus Cereus ◽  
Shelf Life ◽  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
Natural Antimicrobial ◽  
Different Populations ◽  
Citrus Extract ◽  
The Individual

The objectives of the present Doctoral Thesis were: 1) Study of the effect of packaging(aerobic, active and vacuum) and the individual and/or the combined effect of naturalantimicrobial agents (chitosan and natamycin) in prolonging the shelf-life of thetraditional phyllo for Greek style pies 4 ° C. 2) The survival/fate of four pathogens(Listeria spp., Salmonella enterica, Escherichia coli 0157:H7 and Bacillus cereus) wasstudied in the traditional phyllo for Greek style pies and the effect of chitosan (added tophyllo) on those bacteria inoculated into the product at 4ο C. The fate of these fourpathogens on the product was studied at two different populations, 105 cfu/g and 103cfu/g for each pathogen inoculated separately onto the phyllo. 3) : The effect of thepackaging (aerobic and vacuum packaging) and the individual, or the combined effectof natural antimicrobials: Citrus extract (Citrox) and natamycin were studied, inextending the shelf-life of a Greek fresh deli salad (tzatziki: a Traditional Greek salad),during storage under refrigeration (4 ° C). 4) Finally in the last chapter, thegrowth/survival of four pathogens (Listeria spp., Salmonella enterica, Escherihia coli0157:H7 and Bacillus cereus) inoculated at a population into tzatziki of 106 cfu/g andthe effect of 'natural' antimicrobial agent Citrox in these pathogenic microorganismswas studied. Experiments were performed at 4 οC and 10 οC. The addition of Chitosanand citruw extract (with or without natamycin) increased the shelf-life of phyllo andtzatziki, respectively. Βoth antimicrobial agents significantly reduced the population ofall pathogen bacteria.

scholarly journals Antimicrobial and disinfectant resistance of Salmonella Heidelberg from Brazilian flocks did not increase for ten years (2006-2016)

2021 ◽  
Vol 41 ◽  
Author(s):  
Juliana Bassani ◽  
Mariana Paravisi ◽  
Daiane E. Wilsmann ◽  
Karen A. Borges ◽  
Thales Q. Furian ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Sodium Hypochlorite ◽  
High Resistance ◽  
Benzalkonium Chloride ◽  
Antimicrobial Agents ◽  
Food Products ◽  
Foodborne Illness ◽  
Poultry Farm ◽  
Disinfectant Resistance ◽  
Salmonella Heidelberg

ABSTRACT: Salmonella is a major cause of foodborne illness worldwide, and poultry and its derived products are the most common food products associated with salmonellosis outbreaks. Some countries, including Brazil, have experienced an increased prevalence of Salmonella Heidelberg among their poultry flocks. Some isolates have also presented high resistance to antimicrobial agents and persist in the poultry farm environment. This study aimed to compare the susceptibility of S. Heidelberg strains isolated in 2006 with those isolated in 2016 against disinfectants and antimicrobial agents. The results showed that all the strains were highly susceptible to sodium hypochlorite, regardless of the conditions and year of isolation. Resistance to benzalkonium chloride varied according to the conditions applied, but not to the year of isolation. Increased antimicrobial resistance from 2006-2016 was observed only for tetracycline. The results suggest that the antimicrobial and disinfectant resistance of S. Heidelberg did not increase for ten years (2006-2016). However, further analysis should include a larger number of S. Heidelberg isolates from poultry origin and additional antimicrobial agents for more precise conclusions about the increasing in antimicrobial resistance in the last years.

Antimicrobial Resistance of Enterococci Isolated from Mastitic Bovine Milk Samples in Korea

2009 ◽  
Vol 57 (7-8) ◽  
pp. e59-e64 ◽  
Author(s):  
H. M. Nam ◽  
S. K. Lim ◽  
J. S. Moon ◽  
H. M. Kang ◽  
J. M. Kim ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bovine Milk ◽  
Milk Samples

scholarly journals Antimicrobial resistance and detection of mecA and blaZ genes in coagulase-negative Staphylococcus isolated from bovine mastitis

2012 ◽  
Vol 32 (8) ◽  
pp. 692-696 ◽  
Author(s):  
Lidiane C. Soares ◽  
Ingrid A. Pereira ◽  
Bruno R. Pribul ◽  
Marcelo S. Oliva ◽  
Shana M.O. Coelho ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Meca Gene ◽  
Bovine Milk ◽  
Bovine Mastitis ◽  
Coagulase Negative Staphylococcus ◽  
Antimicrobial Resistance Profile ◽  
Disk Diffusion Assay ◽  
Resistance Rates ◽  
Gene 4

The present study evaluated the pheno- and genotypical antimicrobial resistance profile of coagulase-negative Staphylococcus (CNS) species isolated from dairy cows milk, specially concerning to oxacillin. Of 100 CNS isolates, the S. xylosus was the prevalent species, followed by S. cohnii, S. hominis, S. capitis and S. haemolyticus. Only 6% were phenotypically susceptible to the antimicrobial agents tested in disk diffusion assay. Penicillin and ampicillin resistance rates were significantly higher than others antimicrobials. Four isolates were positive to mecA gene (4%), all represented by the S. xylosus species. The blaZ gene was detected in 16% of the isolates (16/100). It was noticed that all mecA + were also positive to this gene and the presence of both genes was correlated to phenotypic beta-lactamic resistance. We conclude that CNS species from bovine milk presented significantly distinct antimicrobial resistance profiles, evaluated by phenotypic and genotypic tests, which has implications for treatment and management decisions.

scholarly journals Mechanisms of antimicrobial resistance development in bacteria

2020 ◽  
Vol 8 (3) ◽  
pp. 226-236
Author(s):  
T. I. Stetsko ◽  
V. P. Muzyka ◽  
M. R. Kozak
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agent ◽  
Resistance Genes ◽  
Target Genes ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Animal Health ◽  
Significant Risk ◽  
Animal Origin

Antimicrobial resistance poses a significant risk to animal health by reducing the effectiveness of the treatment and prevention of many infections caused by bacteria. Antibiotic resistance threatens human health by transmitting resistant strains of microorganisms or resistance genes from animals to humans through the food chain. Life-threatening infections that were previously manageable can become incurable through antimicrobial resistance. Antimicrobial resistance can be divided into two main types: natural and acquired. Natural bacterial resistance is associated with the absence or inaccessibility of target cites for the action of certain antimicrobial agents. The acquired resistance is specific and associated with the acquisition of extraneous resistance genes or mutational modification of chromosomal target genes. The resistance of bacteria to antimicrobial drugs varies depending on the antimicrobial agent, species or genus of bacteria, and the mechanism of resistance. Resistance to the same antimicrobial agent can be mediated by different resistance mechanisms. In some cases, the same resistance gene or mechanism are related to a wide variety of bacteria, whereas in other cases, resistance genes or mechanisms are restricted to certain bacterial species or genera. Bacterial resistance to different classes of antibiotics with common mechanisms often leads to the multidrug resistance. The data presented in this review focuses exclusively on the resistance genes and mechanisms found in bacteria of animal origin and on antimicrobials used in the veterinary medicine. For better coverage of the topic, information on the mechanisms of resistance is presented separately for each class of antimicrobial agents.

scholarly journals Antibiotic Resistance inStaphylococcus aureusand Coagulase Negative Staphylococci Isolated from Goats with Subclinical Mastitis

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Salvatore Virdis ◽  
Christian Scarano ◽  
Francesca Cossu ◽  
Vincenzo Spanu ◽  
Carlo Spanu ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Staphylococcus Epidermidis ◽  
Antimicrobial Agents ◽  
Methicillin Resistance ◽  
Subclinical Mastitis ◽  
Resistance Rate ◽  
Coagulase Negative Staphylococci ◽  
Milk Samples ◽  
Gene Coding ◽  
Resistance Patterns

Antimicrobial resistance patterns and gene coding for methicillin resistance (mecA) were determined in 25S. aureusand 75 Coagulase Negative Staphylococci (CNS) strains isolates from half-udder milk samples collected from goats with subclinical mastitis. Fourteen (56.0%)S. aureusand thirty-one (41.3%) CNS isolates were resistant to one or more antimicrobial agents.S. aureusshowed the highest resistance rate against kanamycin (28.0%), oxytetracycline (16.0%), and ampicillin (12.0%). The CNS tested were more frequently resistant to ampicillin (36.0%) and kanamycin (6.7%). Multiple antimicrobial resistance was observed in eight isolates, and oneStaphylococcus epidermidiswas found to be resistant to six antibiotics. ThemecAgene was not found in any of the tested isolates. Single resistance againstβ-lactamics or aminoglicosides is the most common trait observed while multiresistance is less frequent.

Phenotypic and genotypic antimicrobial resistance of staphylococci from bovine milk

2012 ◽  
Vol 15 (4) ◽  
pp. 677-683 ◽  
Author(s):  
B. Kot ◽  
M. Piechota ◽  
K.M. Wolska ◽  
A. Frankowska ◽  
E. Zdunek ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bovine Milk ◽  
Clinical Mastitis ◽  
Coagulase Negative Staphylococci ◽  
Similar Frequency ◽  
Methicillin Resistant ◽  
Phenotypic Resistance ◽  
Milk Samples ◽  
Resistant Strains ◽  
Subclinical Symptoms

AbstractThe aim of this study was to examine phenotypic and genotypic antimicrobial resistance of staphylococci from milk samples from cows with subclinical and clinical mastitis and from cows without mastitis symptoms to methicillin, tetracyclines, macrolides and lincosamides (ML). Of 207 strains, including 34S. aureusand 173 coagulase-negative staphylococci (CNS), 11 (6.4%) CNS strains were phenotypically resistant to methicillin. ThemecAgene was detected by PCR only in twoS. xylosusstrains and one strain ofS. epidermidisandS. simulans. No methicillin-resistantS. aureusstrains were observed. In methicillin-resistant strains withmecA,gene resistance to other investigated antibiotics was not observed. Phenotypic resistance to tetracycline was detected in 11.0% of CNS strains and 47.4% of them carried thetetKgene. Of 173 CNS strains studied, 27 (15.6%) were resistant to at least one ML antibiotic. The resistance geneermCwas detected in 55.5% of the 27 ML-resistant strains. TheermAandermBgenes were detected in 14.8% and 11.1% of ML-resistant CNS strains, respectively. Antimicrobial resistance to methicillin, tetracyclines and macrolides was detected more frequently in staphylococcal strains from clinical mastitis compared to animals with subclinical symptoms and without mastitis, while the resistance to lincosamides showed a similar frequency in all groups of cows. In conclusion, CNS species from bovine milk differ in phenotypic and genotypic antimicrobial resistance profiles, and the use of PCR technique alone for the detection of methicillin, macrolide, lincosamide and tetyracycline resistance in CNS from cattle is not reliable.

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